Communication Protocols - AERMEC GLFI10M Manuel D'utilisation

TTL NETWORK RESTRICTIONS
The restriction regards the management of the regulation dead band. As a matter of fact, it is sufficient to set the dead band on the
master unit in that it will be ignored on the save units since both the setpoint and the operating season depends on the master in any
case.
EMERGENCY OPERATION OF THE TTL NETWORK
Ambient Probe not fitted on the Master Unit
The operating principle of the master thermostat when it functions without the ambient probe (or with a fault in its own probe) is
described in the paragraphs ambient probe not fitted (2 pipes) and ambient probe not fitted (4 pipes).
Ambient Probe not fitted on the Slave Unit
The Slave thermostat cards go into emergency function if there is a fault in not only the slave unit's probe but also that of the master
unit. In fact, according to what has been stated before, if the slave unit's probe fails while the master unit's probe operates properly,
the slave units will continue to operate using that of the master unit. However, if the slave units begin to operate in emergency mode
they should be made to operate at the speed selected in the user interface and the valve will be opened (for Y1 2-pipe and 4-pipe
systems). In addition, when operating in emergency mode, the slave units do not follow the logic of ON-OFF cycles based on the
position of the temperature selector, but they are always in the ON phase with the ventilation always functioning.
Anti-freeze protection, TTL network
Master: as detailed in the paragraph "Anti-freeze protection" the thermostat provides a series of controls on the ambient temperature
in order to prevent it from dropping to freezing values. If the master unit is operating in this state, it will make all the slave units
operate in AUTO mode with a setpoint of 12°C, even if they are functioning in normal operation mode.
Slave: If one of the slave units is in the operating logic according to anti-freeze protection (even if the master illogically operates in
normal mode), it will begin to operate in AUTO mode with a setpoint of 12°C. This is the only case in which the slave unit operates
according to settings different from those imposed by the master unit.

COMMUNICATION PROTOCOLS

The control card for GLL grills has been designed to connect with control and/or monitoring systems through two communication
buses:
• Modbus RTU
• LonWork
For further information on the technical specifications (physical connections, data exchanges, system settings) of these protocols,
please see specific documentation on the subject.
SERIAL RS485 MONITORING NETWORK
It is possible to interface GLF grid thermostats with a centralised system through a serial protocol based on electrical standard RS485
and using standard protocol Modbus RTU. The thermostat card is always a communication slave.
Network features
• Max. bus length = 1000m
• Transmission speed = 19200 baud.
• Data bits: 8
• No parity
• 2 stop bit
• Modbus RTU communication protocol.
Operating logic
With a communication system, including monitoring system, and the comfort functional automatically enabled, the thermostat
interface's local setpoint value has a variation of ±3 o ±6 °C from the centralised set point
on the VMF-E4 panel or on the VMF-IO expansion card. With a VMF-IR remote control, the setpoint value is the absolute value set by
the infrared device, if there are no "forced settings" received from the monitoring system.
NB: GLF grid thermostats can communicate with the centralised system only if the have:
• VMF-E4 user interface
• VMF-IO expansion card
• VMF-IR remote control
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